1. Field of the Invention
The present invention relates to a printing cylinder which is covered at the outside with a layer of a thermoplastic elastomeric composition. The layer can be hardened by light and is formed by attaching a covering material in sheet form to the cylinder surface under the influence of heat and pressure.
2. Description of the Prior Art
A printing cylinder of this type is known in the art. To manufacture such a known cylinder a sheet of covering material is attached to the cylinder surface prior to exposure to light in such a way that the edges of the sheet which are to be joined are very close fitting to each other, which is accomplished by forming a certain shape to both edges. When the thermoplastic sheet has been wrapped around the cylinder, the sheet is attached to the cylinder surface by application of heat and pressure to the sheet, during which operation also the two edges are attached to each other.
This known printing cylinder has the drawback that due to the application of mechanical pressure at relatively high temperatures, an unevenness in the covering is easily introduced which must therefore be removed by subsequent grinding operations.
Additionally, inclusion of air between the covering layer and the cylinder surface is frequently observed.